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UNITED STATES PATENT IFICE.\\`

SAMUEL SHEPHERD AND AMMI M. GEORGE, OF NASHUA, N. H., ASSIGNORS TO SAMUEL SHEPHERD AND JOSEPH GREELEY, OF SAME PLAGE.

BURNISHER FOR ENAMELED PAPER.

Specification forming part of Letters Patent No. 82,883, dated October 6, 1868.

To all whom it may concern:

Be it known that we, SAMUEL SHEPHERD and AMMI M. GEORGE, both of Nashua, in the county of Hillsborough and State of New Hampshire, have invented a new and useful Improvement in Polishing Surfaces or Devices applicable to Burnishin g or Polishing Enameled Paper and other materials, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification, and in Whichv Figures l and 2 represent a longitudinal view and transverse section of a burnishingroll constructed in accordance with our invention, similar letters of reference indicating similar parts in both figures.

In polishing enameled paper it has long been a desideratum to produce a polishing or burnishing surface which should possess the necessary qualifications in every respect. These are hardness, with closeness or iineness of grain, and freedom from holding dust or dirt, or of being scratched or marked, and presentin g a smoothness or glaze. Metal burnishing-surfaces, however highly polished, are apt to mark and soil the enameled surface of the paper, while glass as a burnishing material, though generally free from such defect, is liable to chip or fracture, and notwithstanding such may be used to advantage in certain cases, it is desirable to fmd a material for the purpose named which is harder than glass and possesses the other requisites already mentioned, to give, under a heavy pressure, the desired polish to the paper. This desideratum it has been a matter of considerable experiment on our part to discover; but the result of our investigations go to prove that the most eligible material for the purpose is a hard and close-grained stoneware. Such may be variously made; but the following description will suflice to explain how the same may be produced with signal advantage in its application to the purpose named, as our experiments with the same have fully demonstrated.

Thus, we take, say, five (5) parts, or thereabout, in measure, of iiint, and four (4) parts, or thereabout of feldspar, both properly ground or reduced to a powder after being calcined, and mix the same with about eleven parts of white or potters clay and a sufficient quantity of water to produce the necessary consistency, after which the mass is considerably worked orkneaded until it becomes sufficiently fine and solid, when it is molded into the desired form it is required to give the burnishin g surface or device, and which may either be of a cylindrical, straight, or other shaped cha-racter, according to the description of mechanism employed to accomplish the burnishing process, or manner of exposing or subjecting the paper to the action of the burnisher. After this the molded mass is dried thoroughly but gradually-say for eight or nine days-and then put into a furnace and intensely heated for about fty hours, when it is allowed to gradually cool for two or three days, after which the mass is tted and ground as required, and so as to present a true and smooth burnishing-surface, the coarsest sand in grinding the same having scarcely an abrasive, or but little more than a polishing, effect, on account of the hardness of the material.

Of course, materially diiferent-sized masses require different lengths of exposure in drying, &c. 5 but for an ordinary burnishing-roll, such as represented in the drawing, the periods herein named for treatment of the mass will suffice, said mass only covering in extent the peripheral surface of the roll for a sufficient thickness of it.

Thus,in the drawing, c represents the stoneware peripheral portion of a burnishing-roll, A, to which bis the axle or shaft, projecting through or from a metal body or head at its ends.

A burnishing roll or surface thus constructed-that is, made to present a stoneware polishing exterior of the character described-possesses all the requisites hereinbefore specified for polishing enameled paper and various other materials.

By the term stoneware We do not propose to restrict ourselves to any particular combination of minerals, but such products as are commonly known as stoneware,7 stonechina,7 porcelain,&c.

What is here claimed, and desired to be secured by Letters Patent, is-

A polishing surface or device made of stoneware, substantially as specilied.

SAMUEL SHEPHERD. A. M. GEORGE.

Witnesses:

J osEPH GREELEY, REGINA HoL'r. 

